I see someone has hooked you up with a guide while I was trying to find info for you, so I'll leave the how to with that video they mentioned, only thing I will add incase that doesn't is make sure you are earthed, an earth strap is the ideal, but my guess is you wont have one, so try touching the copper pipe of a radiator to earth yourself, memory is a very delicate thing, and you can fry it by handling it without being earthed, that said many people probably aren't even aware of this and handle the stuff daily without any problems, so far anyway, but I would be lacking if I didn't mention it so your aware.
That said I couldn't find much on the acer site, but in the manual for this notebook they show 3 items on the back, there is a long section on the edge, that is the battery as you may well be aware, in which case you will know the sliding switch just above it is the release for the battery, now the part you want to be dealing with is a square section toward one of the ends of the notebook, it doesn't go to the end, but it doesn't look to far from it, maybe an inch (or 2.5cm if you prefer), now as best I can see there are 2 screws on the edge closest to the end of the notebook, at least as far as I can see, incase you have the manual check out page 8, Ah just found a better pic, in the manual go to page 40, they show and explain what to do from there downward, if you don't have the manual, or you don't see what I'm looking at, you can view the manual from
>>>Here<<< it is in pdf format and a direct link, first thing you will see is the pdf manual front page, so if you have a slow connection give it a chance to load, and between that to show you where, and the video to show how you should be set.